ln(1+根号((1+x)/x))dx求不定积分 想了很久没思路

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ln(1+根号((1+x)/x))dx
求不定积分 想了很久没思路

为方便计算,可设 (x+1)/x=u²,则 x=1/(u²-1);
∫ln{1+√[(x+1)/x]} dx=∫ln(1+u)d[1/(u²-1)]=[ln(1+u)]/(u²-1)-∫[1/(u²-1)]*[1/(1+u)]du
=[ln(1+u)]/(u²-1)-(1/4)∫{[1/(u-1)]+[1/(1+u)]+[2/(1+u)²]}du
=[ln(1+u)]/(u²-1)-(1/4){ln(u-1)+ln(1+u)-[2/(1+u)]}
=[ln(1+u)]/(u²-1)-(1/4){ln(u²-1)-[2/(1+u)]}
=x*ln{1+√[(x+1)/x]} + (1/4)lnx + 2/{1+√[(x+1)/x]};